基于遥感生态指数的神东矿区1990—2022年煤炭开采对生态环境的影响分析

Impact analysis of coal mining on ecological environment in Shendong Mining area from 1990 to 2022 based on RSEI

定量分析煤矿开采、土地复垦等人类活动对环境产生的影响可为矿区环境保护提供复垦依据。基于1990—2022年Landsat影像,采用遥感生态指数RSEI评估神东矿区的生态环境时空动态演变特征,并利用随机森林模型建立温度、降雨、潜在蒸散发与RSEI的关系模型,得到气候条件下RSEI的预测值R′SEI,结合残差分析与基于Landsat的干扰和恢复趋势检测(Landtrendr)算法定量评估人类活动的影响。结果表明:①矿区与矿井尺度的整体RSEI均值皆有所上升,但矿井尺度RSEI均值低于矿区尺度;2018—2022年光伏区RSEI下降速率为-0.027,略低于控制区,表明神东矿区整体生态环境得到略微改善,但人为采矿活动导致矿井尺度生态环境质量低于矿区尺度,而光伏区的建设对生态环境起到了改善作用。②神东矿区采矿前(1990—1996年)和采矿后(1996—2022年)R′SEI与实际RSEI的相关系数R^(2)为0.61。矿区生态环境在只受气候因素影响下呈变好趋势。③采矿后(1996—2022年),矿区尺度残差δ均值为0.07,δ<0的部分主要集中在矿区北部矿井集中区及其周边地区,占总面积的39.74%,每当矿区有新矿活动加入,δ<0的面积占比就会大幅增加;矿井尺度整体δ均值在1996—2000年呈下降趋势,2000—2012年呈上升趋势,2012—2022年呈下降趋势。④1990—2022年矿区尺度扰动和恢复强度均值分别为0.45、0.37,矿井尺度扰动和恢复强度均值分别为0.43、0.37,矿井尺度扰动强度低于矿区尺度但恢复强度与其相近;采矿后(1996—2022年),扰动与恢复面积占比都保持先上升后下降趋势,表明矿区扰动和恢复行为总是伴随发生且煤炭开采所产生的扰动可由生态遭到破坏后的自我修复及人类复垦行为进行抵消。矿区扰动持续时间占比最大为1 a,恢复持续时间最大为16 a,表明研究区的采矿扰动为急剧的采矿干扰事件,短暂采矿干扰影响发生之后,便有恢复事件发生,且人为对矿区采取的修复行为具有长期性和持续性。综上所述,煤矿开采行为对矿区生态环境造成较强的负面影响,但人类对矿区生态采取的各种治理措施及环境自身的修复能力可对其进行修复。该研究有助于理解煤炭开采对矿区生态环境的影响,并为神东矿区生态环境质量的恢复与提升提供科学依据。

Quantitative analysis of the impact of human activities such as coal mining and land reclamation on the envi-ronment can provide a basis for environmental protection in mining areas.Based on Landsat images from 1990 to 2022,remote sensing ecological index(RSEI)was used to evaluate the temporal and spatial dynamic evolution charac-teristics of the ecological environment in Shendong mining area.The relationship model between temperature,rainfall and RSEI was further established by using random forest model,and the predicted value of R′SEI under climatic condi-tions was obtained.Residual analysis and Landtrendr algorithm were combined to quantitatively assess the impact of human activities.The results show that:①The average RSEI of mine scale and mine scale is higher,but the average RSEI of mine scale is lower than mine scale.From 2018 to 2022,the RSEI decline rate of the photovoltaic area is-0.027,slightly lower than that of the control area,indicating that the overall ecological environment of the Shen-dong mining area has been slightly improved,but the ecological environment quality at the mine scale is lower than that at the mining area,and the construction of the photovoltaic area has played a role in improving the ecological environment.②The correlation coefficient R^(2) between the actual RSEI before(1990-1996)and after(1996-2022)mining in Shendong Mining area is 0.61.The ecological environment of the mining area has a good trend un-der the influence of climate factors only.③After mining(1996-2022),the average residualδof mining area scale is 0.07,and the part of δ<0 is mainly concentrated in the mine concentration area in the north of the mining area and its surrounding areas,accounting for 39.74% of the total area.When new mining activities are added to the mining area,the proportion of δ<0 area will increase significantly.The overall δ-value of mine scale showed a decrea-sing trend from 1996 to 2000,an increasing trend from 2000 to 2012,and a decreasing trend from 2012 to 2022.④From 1990 to 2022,the mean values of scale disturbance and recovery intensity in mining area are 0.45 and 0.37,respectively,while the mean values of mine scale disturbance and recovery intensity are 0.43 and 0.37,respectively.The intensity of mine scale disturbance is lower than mine scale but similar to mine scale recovery intensity.After min-ing(1996-2022),the proportion of disturbance and restoration area both increased first and then decreased,indica-ting that disturbance and restoration behavior of mining area always occur together,and the disturbance caused by coal mining can be offset by self-restoration and human reclamation behavior after ecological damage.The maxi-mum duration of disturbance in the mining area is 1 a,and the maximum duration of recovery is 16 a,indicating that the mining disturbance in the study area is a sharp mining disturbance event.After the occurrence of temporary mining disturbance,there will be recovery events,and the artificial restoration behavior of the mining area is long-term and sustainable.To sum up,coal mining behavior has a strong negative impact on the ecological envi-ronment of the mining area,but it can be repaired by various measures taken by human beings and the restoration a-bility of the environment itself.This study is helpful to understand the impact of coal mining on the ecological environ-ment of the mining area,and provides a scientific basis for the restoration and improvement of the ecological environ-ment quality of Shendong Mining Area.